diff --git a/tox.ini b/tox.ini
index 316c5b784..55b8440df 100644
--- a/tox.ini
+++ b/tox.ini
@@ -82,12 +82,12 @@ commands=
 [testenv:py27-trial]
 deps=twisted
 commands=
-  py.test -ra {posargs:testing/test_unittest.py}
+  pytest -ra {posargs:testing/test_unittest.py}
 
 [testenv:py35-trial]
 deps={[testenv:py27-trial]deps}
 commands=
-  py.test -ra {posargs:testing/test_unittest.py}
+  pytest -ra {posargs:testing/test_unittest.py}
 
 [testenv:doctest]
 commands=pytest --doctest-modules _pytest